Div1b

ABSTRACT

The invention provides Divlb polypeptides and DNA (RNA) encoding Divlb polypeptides and methods for producing such polypeptides by recombinant techniques. Also provided are methods for utilizing Divlb polypeptides to screen for antibacterial compounds.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 08/827,615, filed Apr. 9, 1997. This application claims benefit of 60/034,588 filed Jan. 2, 1997.

FIELD OF THE INVENTION

This invention relates to newly identified polynucleotides and polypeptides, and their production and uses, as well as their variants, agonists and antagonists, and their uses. In particular, in these and in other regards, the invention relates to novel polynucleotides and polypeptides of the div (cell division) family, hereinafter referred to as "Divlb".

BACKGROUND OF THE INVENTION

It is particularly preferred to employ Staphylococcal genes and gene products as targets for the development of antibiotics. The Staphylococci make up a medically important genera of microbes. They are known to produce two types of disease, invasive and toxigenic. Invasive infections are characterized generally by abscess formation effecting both skin surfaces and deep tissues. S. aureus is the second leading cause of bacteremia in cancer patients. Osteomyelitis, septic arthritis, septic thrombophlebitis and acute bacterial endocarditis are also relatively common. There are at least three clinical conditions resulting from the toxigenic properties of Staphylococci. The manifestation of these diseases result from the actions of exotoxins as opposed to tissue invasion and bacteremia. These conditions include: Staphylococcal food poisoning, scalded skin syndrome and toxic shock syndrome

The frequency of Staphylococcus aureus infections has risen dramatically in the past 20 years. This has been attributed to the emergence of multiply antibiotic resistant strains and an increasing population of people with weakened immune systems. It is no longer uncommon to isolate Staphylococcus aureus strains which are resistant to some or all of the standard antibiotics. This has created a demand for both new anti-microbial agents and diagnostic tests for this organism.

Divlb (designated FtsQ in E. coli and divlb in B. subtilus) is an essential gene involved in bacterial cell division. E. coli FtsQ has been identified as a DivlB homolog, being 18% identical and 44% similar (Harry et al., (1994) Gene 147 85-89). It has been shown in E. coli that FtsQ is required through out the whole process of septum formation during cell division. FtsQ is a simple cytoplasmic membrane protein with approx 21 amino acids in the cytoplasmic domain, 25 amino acids in the cytoplasmic membrane and approx. 230 amino acids in the periplasmic domain (Carson et al., 1991, J. Bacteriol 173: 2187-2195). It is estimated that FtsQ is present at about 20 copies/cell (Carson et al., 1991, J. Bacteriol. 173: 2187-2195). DivlB of B. subtilus 168 is also essential for viability at 37° C. and above and is required at all temperatures for the normal rate of cell division (Beall and Lutkenhaus, 1989, J. Bacteriol. 171: 6821-6834). An FtsQ-MalG fusion protein, where the cytoplasmic and the most of the membrane spanning regions of FtsQ were replaced with similar domains of Mal G, has been shown to complement an FtsQ temperature sensitive mutant. This suggests that the cytoplasmic and membrane spanning regions of FtsQ may not be required for protein function (Dai et al., 1996, 178, 1328-1334). However, a portion of the membrane spanning region of FtsQ as required to transport the protein to the periplasm. In contrast, a report by Guzman et al., 1997 (J. Bacteriol. 179, 5094) suggests that only the membrane-spanning segment of ftsQ can be replaced and the cytoplasmic domain is essential for function. Descoteaux and Drapeau et al., 1987 (J. Bacteriol 169, 1938) have suggested that FtsQ may interact with FtsZ. The biochemical function of FtsQ is not known.

Clearly, there is a need for factors, such as the novel compounds of the invention, that have a present benefit of being useful to screen compounds for antibiotic activity. Such factors are also useful to determine their role in pathogenesis of infection, dysfunction and disease. There is also a need for identification and characterization of such factors and their antagonists and agonists which can play a role in preventing, ameliorating or correcting infections, dysfunctions or diseases.

The polypeptides of the invention have amino acid sequence homology to a known FtsQ in E. coli and Divlb in B. subtilus protein.

SUMMARY OF THE INVENTION

It is an object of the invention to provide polypeptides that have been identified as novel Divlb polypeptides by homology between the amino acid sequence set out in Table 1 [SEQ ID NO: 2] and a known amino acid sequence or sequences of other proteins such as FtsQ in E. coli and Divlb in B. subtilus protein.

It is a further object of the invention to provide polynucleotides that encode Divlb polypeptides, particularly polynucleotides that encode the polypeptide herein designated Divlb.

In a particularly preferred embodiment of the invention the polynucleotide comprises a region encoding Divlb polypeptides comprising the sequence set out in Table 1 [SEQ ID NO:1] which includes a full length gene, or a variant thereof.

In another particularly preferred embodiment of the invention there is a novel Divlb protein from Staphylococcus aureus comprising the amino acid sequence of Table 1 [SEQ ID NO:2], or a variant thereof.

In accordance with another aspect of the invention there is provided an isolated nucleic acid molecule encoding a mature polypeptide expressible by the Staphylococcus aureus WCUH 29 strain contained in the deposited strain.

A further aspect of the invention there are provided isolated nucleic acid molecules encoding Divlb, particularly Staphylococcus aureus Divlb, including mRNAs, cDNAs, genomic DNAs. Further embodiments of the invention include biologically, diagnostically, prophylactically, clinically or therapeutically useful variants thereof, and compositions comprising the same.

In accordance with another aspect of the invention, there is provided the use of a polynucleotide of the invention for therapeutic or prophylactic purposes, in particular genetic immunization. Among the particularly preferred embodiments of the invention are naturally occurring allelic variants of Divlb and polypeptides encoded thereby.

Another aspect of the invention there are provided novel polypeptides of Staphylococcus aureus referred to herein as Divlb as well as biologically, diagnostically, prophylactically, clinically or therapeutically useful variants thereof, and compositions comprising the same.

Among the particularly preferred embodiments of the invention are variants of Divlb polypeptide encoded by naturally occurring alleles of the Divlb gene.

In a preferred embodiment of the invention there are provided methods for producing the aforementioned Divlb polypeptides.

In accordance with yet another aspect of the invention, there are provided inhibitors to such polypeptides, useful as antibacterial agents, including, for example, antibodies.

In accordance with certain preferred embodiments of the invention, there are provided products, compositions and methods for assessing Divlb expression, treating disease, for example, disease, such as, infections of the upper respiratory tract (e.g., otitis media, bacterial tracheitis, acute epiglottitis, thyroiditis), lower respiratory (e.g., empyema, lung abscess), cardiac (e.g., infective endocarditis), gastrointestinal (e.g., secretory diarrhoea, splenic absces, retoperitoneal abscess), CNS (e.g., cerebral abscess), eye (e.g., blepharitis, conjunctivitis, keratitis, endophthalmitis, preseptal and orbital cellulitis, darcryocystitis), kidney and urinary tract (e.g., epididymitis, intrarenal and perinephric absces, toxic shock syndrome), skin (e.g., impetigo, folliculitis, cutaneous abscesses, cellulitis, wound infection, bacterial myositis) bone and joint (e.g., septic arthritis, osteomyelitis), assaying genetic variation, and administering a Divlb polypeptide or polynucleotide to an organism to raise an immunological response against a bacteria, especially a Staphylococcus aureus bacteria

In accordance with certain preferred embodiments of this and other aspects of the invention there are provided polynucleotides that hybridize to Divlb polynucleotide sequences, particularly under stringent conditions.

In certain preferred embodiments of the invention there are provided antibodies against Divlb polypeptides.

In other embodiments of the invention there are provided methods for identifying compounds which bind to or otherwise interact with and inhibit or activate an activity of a polypeptide or polynucleotide of the invention comprising: contacting a polypeptide or polynucleotide of the invention with a compound to be screened under conditions to permit binding to or other interaction between the compound and the polypeptide or polynucleotide to assess the binding to or other interaction with the compound, such binding or interaction being associated with a second component capable of providing a detectable signal in response to the binding or interaction of the polypeptide or polynucleotide with the compound; and determining whether the compound binds to or otherwise interacts with and activates or inhibits an activity of the polypeptide or polynucleotide by detecting the presence or absence of a signal generated from the binding or interaction of the compound with the polypeptide or polynucleotide.

In accordance with yet another aspect of the invention, there are provided Divlb agonists and antagonists, preferably bacteriostatic or bactericidal agonists and antagonists.

In a further aspect of the invention there are provided compositions comprising a Divlb polynucleotide or a Divlb polypeptide for administration to a cell or to a multicellular organism

Various changes and modifications within the spirit and scope of the disclosed invention will become readily apparent to those skilled in the art from reading the following descriptions and from reading the other parts of the present disclosure.

GLOSSARY

The following definitions are provided to facilitate understanding of certain terms used frequently herein.

"Host cell" is a cell which has been transformed or transfected, or is capable of transformation or transfection by an exogenous polynucleotide sequence.

"Identity," as known in the art, is a relationship between two or more polypeptide sequences or two or more polynucleotide sequences, as determined by comparing the sequences. In the art, "identity" also means the degree of sequence relatedness between polypeptide or polynucleotide sequences, as the case may be, as determined by the match between strings of such sequences. "Identity" and "similarity" can be readily calculated by known methods, including but not limited to those described in (Computational Molecular Biology, Lesk, A. M., ed., Oxford University Press, New York, 1988; Biocomputing: Informatics and Genome Projects, Smith, D. W., cd, Academic Press, New York, 1993; Computer Analysis of Sequence Data, Part I, Griffin, A. M., and Griffin, H. G., eds., Humana Press, New Jersey, 1994; Sequence Analysis in Molecular Biology, von Heinje, G., Academic Press, 1987; and Sequence Analysis Primer, Gribskov, M. and Devereux, J., eds., M Stockton Press, New York, 1991; and Carillo, H., and Lipman, D., SIAM J. Applied Math., 48: 1073 (1988). Preferred methods to determine identity are designed to give the largest match between the sequences tested. Methods to determine identity and similarity are codified in publicly available computer programs. Preferred computer program methods to determine identity and similarity between two sequences include, but are not limited to, the GCG program package (Devereux, J., et al., Nucleic Acids Research 12(1): 387 (1984)), BLASTP, BLASTN, and FASTA (Atschul, S. F. et al., J. Molec. Biol. 215: 403-410 (1990). The BLAST X program is publicly available from NCBI and other sources (BLAST Manual, Altschul, S., et al., NCBI NLM NIH Bethesda, Md. 20894; Altschul, S., et al., J. Mol. Biol. 215: 403-410 (1990). As an illustration, by a polynucleotide having a nucleotide sequence having at least, for example, 95% "identity" to a reference nucleotide sequence of SEQ ID NO: 1 it is intended that the nucleotide sequence of the polynucleotide is identical to the reference sequence except that the polynucleotide sequence may include up to five point mutations per each 100 nucleotides of the reference nucleotide sequence of SEQ ID NO: 1. In other words, to obtain a polynucleotide having a nucleotide sequence at least 95% identical to a reference nucleotide sequence, up to 5% of the nucleotides in the reference sequence may be deleted or substituted with another nucleotide, or a number of nucleotides up to 5% of the total nucleotides in the reference sequence may be inserted into the reference sequence. These mutations of the reference sequence may occur at the 5' or 3' terminal positions of the reference nucleotide sequence or anywhere between those terminal positions, interspersed either individually among nucleotides in the reference sequence or in one or more contiguous groups within the reference sequence. Analogously, by a polypeptide having an amino acid sequence having at least, for example, 95% identity to a reference amino acid sequence of SEQ ID NO:2 is intended that the amino acid sequence of the polypeptide is identical to the reference sequence except that the polypeptide sequence may include up to five amino acid alterations per each 100 amino acids of the reference amino acid of SEQ ID NO: 2. In other words, to obtain a polypeptide having an amino acid sequence at least 95% identical to a reference amino acid sequence, up to 5% of the amino acid residues in the reference sequence may be deleted or substituted with another amino acid, or a number of amino acids up to 5% of the total amino acid residues in the reference sequence may be inserted into the reference sequence. These alterations of the reference sequence may occur at the amino or carboxy terminal positions of the reference amino acid sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in one or more contiguous groups within the reference sequence.

"Isolated" means altered "by the hand of man" from its natural state, ie., if it occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or a polypeptide naturally present in a living organism is not "isolated," but the same polynucleotide or polypeptide separated from the coexisting materials of its natural state is "isolated", as the term is employed herein.

"Polynucleotide(s)" generally refers to any polyribonucleotide or polydeoxribonucleotide, which may be unmodified RNA or DNA or modified RNA or DNA. "Polynucleotide(s)" include, without limitation, single- and double-stranded DNA, DNA that is a mixture of single and double-stranded regions or single, double- and triple-stranded regions, single- and double-stranded RNA, and RNA that is mixture of single- and double-stranded regions, hybrid molecules comprising DNA and RNA that may be single-stranded or, more typically, double-stranded, or triple-stranded regions, or a mixture of single- and double-stranded regions. In addition, "polynucleotide" as used herein refers to triple-stranded regions comprising RNA or DNA or both RNA and DNA. The strands in such regions may be from the same molecule or from different molecules. The regions may include all of one or more of the molecules, but more typically involve only a region of some of the molecules. One of the molecules of a triple-helical region often is an oligonucleotide. As used herein, the term "polynucleotide(s)" also includes DNAs or RNAs as described above that contain one or more modified bases. Thus, DNAs or RNAs with backbones modified for stability or for other reasons are "polynucleotide(s)" as that term is intended herein. Moreover, DNAs or RNAs comprising unusual bases, such as inosine, or modified bases, such as tritylated bases, to name just two examples, are polynucleotides as the term is used herein. It will be appreciated that a great variety of modifications have been made to DNA and RNA that serve many useful purposes known to those of skill in the art The term "polynucleotide(s)" as it is employed herein embraces such chemically, enzymatically or metabolically modified forms of polynucleotides, as quell as the chemical forms of DNA and RNA characteristic of viruses and cells, including, for example, simple and complex cells. "Polynucleotide(s)" also embraces short polynucleotides often referred to as oligonucleotide(s).

"Polypeptide(s)" refers to any peptide or protein comprising two or more amino acids joined to each other by peptide bonds or modified peptide bonds. "Polypeptide(s)" refers to both short chains, commonly referred to as peptides, oligopeptides and oligomers and to longer chains generally referred to as proteins. Polypeptides may contain amino acids other than the 20 gene encoded amino acids. "Polypeptide(s)" include those modified either by natural processes, such as processing and other post-translational modifications, but also by chemical modification techniques. Such modifications are well described in basic texts and in more detailed monographs, as well as in a voluminous research literature, and they are well known to those of skill in the art. It will be appreciated that the same type of modification may be present in the same or varying degree at several sites in a given polypeptide. Also, a given polypeptide may contain many types of modifications. Modifications can occur anywhere in a polypeptide, including the peptide backbone, the amino acid side-chains, and the amino or carboxyl termini. Modifications include, for example, acetylation, acylation, ADP-ribosylation, amidation, covalent attachment of flavin, covalent attachment of a heme moiety, covalent attachment of a nucleotide or nucleotide derivative, covalent attachment of a lipid or lipid derivative, covalent attachment of phosphotidylinositol, cross-linking, cyclization, disuifide bond formation, demethylation, formation of covalent cross-links, formation of cysteine, formation of pyroglutamate, formylation, gamma-carboxylation, glycosylation, GPI anchor formation, hydroxylation, iodination, methylation, myristoylation, oxidation, proteolytic processing, phosphorylation, prenylation, racemization, glycosylation, lipid attachment, sulfation, gamma-carboxylation of glutamic acid residues, hydroxylation and ADP-ribosylation, selenoylation, sulfation, transfer-RNA mediated addition of amino acids to proteins, such as arginylation, and ubiquitination. See, for instance, PROTEINS--STRUCTURE AND MOLECULAR PROPERTIES, 2nd Ed., T. E. Creighton, W. H. Freeman and Company, New York (1993) and Wold, F., Posttranslational Protein Modifications: Perspectives and Prospects, pgs. 1-12 in POSTTRANSLATIONAL COVALENT MODIFICATION OF PROTEINS, B. C. Johnson, Ed., Academic Press, Nev York (1983); Seifter et al., Meth Enymol. 182:626-646 (1990) and Rattan et al., Protein Synthesis: Posttranslational Modifications and Aging, Ann. N.Y. Acad. Sci. 663: 48-62 (1992). Polypeptides may be branched or cyclic, with or without branching. Cyclic, branched and branched circular polypeptides may result from post-translational natural processes and may be made by entirely synthetic methods, as well.

"Variant(s)" as the term is used herein, is a polynucleotide or polypeptide that differs from a reference polynucleotide or polypeptide respectively, but retains essential properties. A typical variant of a polynucleotide differs in nucleotide sequence from another, reference polynucleotide. Changes in the nucleotide sequence of the variant may or may not alter the amino acid sequence of a polypeptide encoded by the reference polynucleotide. Nucleotide changes may result in amino acid substitutions, additions, deletions, fusions and truncations in the polypeptide encoded by the reference sequence, as discussed below. A typical variant of a polypeptide differs in amino acid sequence from another, reference polypeptide. Generally, differences are limited so that the sequences of the reference polypeptide and the variant are closely similar overall and, in many regions, identical. A variant and reference polypeptide may differ in amino acid sequence by one or more substitutions, additions, deletions in any combination. A substituted or inserted amino acid residue may or may not be one encoded by the genetic code. A variant of a polynucleotide or polypeptide may be a naturally occurring such as an allelic variant, or it may be a variant that is not known to occur naturally. Non-naturally occurring variants of polynucleotides and polypeptides may be made by mutagenesis techniques, by direct synthesis, and by other recombinant methods known to skilled artisans.

DESCRIPTION OF THE INVENTION

The invention relates to novel Divlb polypeptides and polynucleotides as described in greater detail below. In particular, the invention relates to polypeptides and polynucleotides of a novel Divlb of Staphylococcus aureus, which is related by amino acid sequence homology to FtsQ in E. coli and Divlb in B. subtilus polypeptide. The invention relates especially to Divlb having the nucleotide and amino acid sequences set out in Table 1 [SEQ ID NO: 1] and Table 1 [SEQ ID NO: 2] respectively, and to the Divlb nucleotide sequences of the DNA in the deposited strain and amino acid sequences encoded thereby.

                                      TABLE 1                                      __________________________________________________________________________     Div1b Polynucleotide and Polypeptide Sequences                                 __________________________________________________________________________     (A) Sequences from Staphylococcus aureus Div1b polynucleotide sequence         [SEQ ID NO: 1].                                                                5'-1                                                                              ATGGATGATA                                                                             AAACGAAGAA                                                                             CGATCAACAA                                                                             GAATCAAATG                                                                             AAGATAAAGA                                    51 TGAATTAGAA TTATTTACGA GGAATACATC TAAGAAAAGA CGGCAAAGAA                      101 AAAGGTCAAA GGCTACACAT TTTTCTAATC AAAATAAAGA TGATACATCT                     151 CAACAAGCTG ATTTTGATGA AGAAATTTAC TTGATAAATA AAGACTTCAA                     201 AAAAGAAGAA AGCAATGATG AAAATAATGG TTCTGCTTCT AGTCATGCGA                     251 ATGATAATAA TATCGATGAT TCTACAGACT CTAATATTGA AAATGAGGAT                     301 TATAGATATA ATCAAGAAAT TGACGACCAA AATGAATCGA ATGGAATTGC                     351 AGTCGCCAAC GAACAACCTC AATCAGCTCC TAAAGAACAA AATAGCGACT                     401 CGAATGATGA GGAAACAGTA ACGAAAAAAG AGCGAAAAAG TAAAGTAACA                     451 CAATTAAAGC CATTAACACT TGAAGAAAAG CGGAAGTTAA GACGTAAGCG                     501 ACAAAAACGA ATCCAATACA GTGTTATTAC AATATTAGTA TTGTTGATTG                     551 CTGTTATATT AATTTACATG TTTTCACCAC TTAGTAAAAT TGCGCATGTA                     601 AATATAAATG GAAATAATCA CGTTAGTACT TCAAAGATAA ACAAAGTTTT                     651 AGGTGTTAAA AATGATTCGA GGATGTATAC GTTTAGTAAA AAAAATGCTA                     701 TTAATGATCT CGAAGAGGAT CCATTAATCA CAAGTGTTGA GATACACAAG                     751 CAATTCCCAA ACACATTAAA CGTAGATATC ACAGAAAATG AAATTATTGC                     801 TTTAGTGAAA TATAAAGGTA AATATTTACC TTTATTAGAA AATGGTAAAT                     851 TGCTTAAAGG TTCAAATGAT GTCAAAATTA ATGATGCACC TGTCATGGAT                     901 GGTTTCAAAG GTACAAAAGA AGATGATATG ATTAAGGCGT TATCTGAAAT                     951 GACACCTGAA GTTAGACGAT ATATTGCCGA AGTGACATAC CCCCCAAGTA                     1001 AAAACAAACA TAGCAGAATT GAATTGTTTA CGACAGATGG ACTTCAAGTA                    1051 ATCGGTGATA TTTCGACGAT ATCTAAGAAA ATGAAATATT ATCCGCAGAT                    1101 GTCACAATCA TTATCAAGGG ATAGTTCGGG TAAACTAAAA ACAAGAGGCT                    1151 ATATTGATTT ATCAGTCGGT GCTTCATTTA TCCCATACCG TGGAAACACG                    1201 TCTAGTCAAT CAGAAAGCGA TAAAAATGTG ACTAAATCAT CTCAAGAGGA                    1251 AAATCAAGCA AAAGAAGAAT TACAAAGCGT TTTAAACAAA ATTAACAAAC                  1301                                                                              AATCAAGTAA                                                                             GAATAATTAA-3'                                                       (B) Div1b polypeptide sequence deduced from the polynucleotide sequence        in this table                                                                    [SEQ ID NO:2].                                                               NH.sub.2 -1MDDKTKNDQQ                                                                     ESNEDKDELE                                                                             LFTRNTSKKR                                                                             RQRKRSKATH                                                                             FSNQNKDDTS                                  51 QQADFDEEIY                                                                             LINKDFKKEE                                                                             SNDENNGSAS                                                                             SHANDNNIDD                                                                             STDSNIENED                                    101 YRYNQEIDDQ NESNGIAVAN EQPQSAPKEQ NSDSNDEETV TKKERKSKVT                     151 QLKPLTLEEK RKLRRKRQKR IQYSVITILV LLIAVILIYM FSPLSKIAHV                     201 NINGNNHVST SKINKVLGVK NDSRMYTFSK KNAINDLEED PLITSVEIHK                     251 QFPNTLNVDI TENEIIALVK YKGKYLPLLE NGKLLKGSND VKINDAPVMD                     301 GFKGTKEDDM IKALSEMTPE VRRYIAEVTY PPSKNKHSRI ELFTTDGLQV                     351 IGDISTISKK MKYYPQMSQS LSRDSSGKLK TRGYIDLSVG ASFIPYRGNT                   401                                                                               SSQSESDKNV                                                                             TKSSQEENQA                                                                             KEELQSVLNK                                                                             INKQSSKNN--COOH                                     (C) Polynucleotide sequence embodiments [SEQ ID NO:1].                           X-(R.sub.1).sub.n -1                                                            ATGGATGATA                                                                             AAACGAAGAA                                                                             CGATCAACAA                                                                             GAATCAAATG                                                                             AAGATAAAGA                                    51 TGAATTAGAA TTATTTACGA GGAATACATC TAAGAAAAGA CGGCAAAGAA                      101 AAAGGTCAAA GGCTACACAT TTTTCTAATC AAAATAAAGA TGATACATCT                     151 CAACAAGCTG ATTTTGATGA AGAAATTTAC TTGATAAATA AAGACTTCAA                     201 AAAAGAAGAA AGCAATGATG AAAATAATGG TTCTGCTTCT AGTCATGCGA                     251 ATGATAATAA TATCGATGAT TCTACAGACT CTAATATTGA AAATGAGGAT                     301 TATAGATATA ATCAAGAAAT TGACGACCAA AATGAATCGA ATGGAATTGC                     351 AGTCGCCAAC GAACAACCTC AATCAGCTCC TAAAGAACAA AATAGCGACT                     401 CGAATGATGA GGAAACAGTA ACGAAAAAAG AGCGAAAAAG TAAAGTAACA                     451 CAATTAAAGC CATTAACACT TGAAGAAAAG CGGAAGTTAA GACGTAAGCG                     501 ACAAAAACGA ATCCAATACA GTGTTATTAC AATATTAGTA TTGTTGATTG                     551 CTGTTATATT AATTTACATG TTTTCACCAC TTAGTAAAAT TGCGCATGTA                     601 AATATAAATG GAAATAATCA CGTTAGTACT TCAAAGATAA ACAAAGTTTT                     651 AGGTGTTAAA AATGATTCGA GGATGTATAC GTTTAGTAAA AAAAATGCTA                     701 TTAATGATCT CGAAGAGGAT CCATTAATCA CAAGTGTTGA GATACACAAG                     751 CAATTCCCAA ACACATTAAA CGTAGATATC ACAGAAAATG AAATTATTGC                     801 TTTAGTGAAA TATAAAGGTA AATATTTACC TTTATTAGAA AATGGTAAAT                     851 TGCTTAAAGG TTCAAATGAT GTCAAAATTA ATGATGCACC TGTCATGGAT                     901 GGTTTCAAAG GTACAAAAGk AGATGATATG ATTAAGGCGT TATCTGAAAT                     951 GACACCTGAA GTTAGACGAT ATATTGCCGA AGTGACATAC CCCCCAAGTA                     1051 AAAACAAACA TAGCAGAATT GAATTGTTTA CGACAGATGG ACTTCAAGTA                    1051 ATCGGTGATA TTTCGACGAT ATCTAAGAAA ATGAAATATT ATCCGCAGAT                    1101 GTCACAATCA TTATCAAGGG ATAGTTCGGG TAAACTAAAA ACAAGAGGCT                    1151 ATATTGATTT ATCAGTCGGT GCTTCATTTA TCCCATACCG TGGAAACACG                    1201 TCTAGTCAAT CAGAAAGCGA TAAAAATGTG ACTAAATCAT CTCAAGAGGA                    1251 AAATCAAGCA AAAGAAGAAT TACAAAGCGT TTTAAACAAA ATTAACAAAC                  1301                                                                              AATCAAGTAA                                                                             GAATAATTAA--(R.sub.2).sub.n --Y                                     (D) Polypeptide sequence embodiments ]SEQ ID NO:2].                              X--(R.sub.1).sub.n -1                                                           MDDKTKNDQQ                                                                             ESNEDKDELE                                                                             LFTRNTSKKR                                                                             RQRKRSKATH                                                                             FSNQNKDDTS                                    51 QQADFDEEIY LINKDFKKEE SNDENNGSAS SHANDNNIDD STDSNIENED                      101 YRYNQEIDDQ NESNGIAVAN EQPQSAPKEQ NSDSNDEETV TKKERKSKVT                     151 QLKPLTLEEK RKLRRKRQKR IQYSVITILV LLIAVILIYM FSPLSKIAHV                     201 NINGNNHVST SKINKVLGVK NDSRMYTFSK KNAINDLEED PLITSVEIHK                     251 QFPNTLNVDI TENEIIALVK YKGKYLPLLE NGKLLKGSND VKINDAPVMD                     301 GFKGTKEDDM IKALSEMTPE VRRYIAEVTY PPSKNKHSRI ELFTTDGLQV                     351 IGDISTISKK MKYYPQMSQS LSRDSSGKLK TRGYIDLSVG ASFIPYRGNT                   401                                                                               SSQSESDKNV                                                                             TKSSQEENQA                                                                             KEELQSVLNK                                                                             INKQSSKNN--(R.sub.2).sub.n --Y                      (E) Sequences from Staphylococcus aureus Div1b polynucleotide ORF              sequence [SEQ ID NO:3].                                                        5'-1                                                                              ATGAATCGGA                                                                             ATGGAATTGC                                                                             AAGTCGGCAA                                                                             CCGGACCAAC                                                                             CTCAATCAGC                                    51 TCCTAAAGAA CAAAATAGCG ACTCGAATGA TGAGGAAACA GTAACGAAAA                      101 AAGAACGAAA AAGTAAAGTA ACACAATTAA AGCCATTAAC ACTTGAAGAA                     151 AAGCGGAAGT TAAGACGTAA GCGACAAAAA CGAATCCAAT ACAGTGTTAT                     201 TACAATATTA GTATTGTTGA TTGCTGTTAT ATTAATTTAC ATGTTTTCAC                     251 CACTTAGTAA AATTGCGCAT GTAAATATAA ATGGAAATAA TCACGTTAGT                     301 ACTTCAAAGA TAAACAAAGT TTTAGGTGTT AAAAATGATT CGAGGATGTA                     351 TACGTTTAGT AAAAAAAATG CTATTAATGA TCTCGAAGAG GATCCATTAA                     401 TCAAAAGTGT TGAGATACAC AAGCAATTAC CAAACACATT AAACGTAGAT                     451 ATCACAGAAA ATGAAATTAT TGCTTTAGTG AAATATAAAG GTAAATATTT                     501 ACCTTTATTA GAAAATGGTA AATTGCTTAA AGGTTCAAAT GATGTCAAAA                     551 TTAATGATGC ACCTGTCATG GATGGTTTCA AAGGTACAAA AGAAGATGAT                     601 ATGATTAAGG CGTTATCTGA AATGACACCT GAAGTTAGAC GATATATTGC                     651 CGAAGTGACA TACGCCCCAA GTAAAAACAA ACATAGCAGA ATTGAATTGT                     701 TTACGACAGA TGGACTTCAA GTAATCGGTG ATATTTCGAC GATATCTAAG                     751 AAAATGAAAT ATTATCCGCA GATGTCACAA TCATTATCAA GGGATAGTTC                     801 GGGTAAACTA AAAACAAGAG GCTATATTGA TTTATCAGTC GGTGCTTCAT                     851 TTATCCCATA CCGTGGAAAC ACGTCTAGTC AATCAGAAAG CGATAAAAAT                     901 GTGACTAAAT CATCTCAAGA GGAAAATCAA GCAAAAGAAG AATTACAAAG                     951 CGTTTTAAAC AAAATTAACA AACAATCAAG TAAGAATAAT                               3'                                                                            (F) Div1b polypeptide sequence deduced from the polynucleotide ORF             sequence in this table                                                           [SEQ ID NO:4].                                                               NH.sub.2 -1MNRNGIASRQ                                                                     PDQPQSAPKE                                                                             QNSDSNDEET                                                                             VTKKERKSKV                                                                             TQLKPLTLEE                                  51 KRKLRRKRQK                                                                             RIQYSVITIL                                                                             VLLIAVILIY                                                                             MFSPLSKIAH                                                                             VNINGNNHVS                                    101 TSKINKVLGV KNDSRMYTFS KKNAINDLEE DPLIKSVEIH KQLPNTLNVD                     151 ITENEIIALV KYKGKYLPLL ENGKLLKGSN DVKINDAPVM DGFKGTKEDD                     201 MIKALSEMTP EVRRYIAEVT YAPSKNKHSR IELFTTDGLQ VIGDISTISK                     251 KMKYYPQMSQ SLSRDSSGKL KTRGYIDLSV GASFIPYRGN TSSQSESDKN                   301                                                                               VTKSSQEENQ                                                                             AKEELQSVLN                                                                             KINKQSSKNN--COOH                                            __________________________________________________________________________

Deposited Materials

A deposit containing a Staphylococcus aureus WCUH 29 strain has been deposited with the National Collections of Industrial and Marine Bacteria Ltd. (herein "NCIMB"), 23 St Machar Drive, Aberdeen AB2 1RY, Scotland on Sep. 11, 1995 and assigned NCIMB Deposit No. 40771, and is referred to as Staphylococcus aureus WCUH29 on deposit. The Staphylococcus aureus strain deposit is referred to herein as "the deposited strain" or as "the DNA of the deposited strain."

The deposited strain contains the full length Divlb gene. The sequence of the polynucleotides contained in the deposited strain, as vell as the amino acid sequence of the polypeptide encoded thereby, are controlling in the event of any conflict with any description of sequences herein.

The deposit of the deposited strain has been made under the terms of the Budapest Treaty on the International Recognition of the Deposit of Micro-organisms for Purposes of Patent Procedure. The strain will be irrevocably and without restriction or condition released to the public upon the issuance of a patent. The deposited strain is provided merely as convenience to those of skill in the art and is not an admission that a deposit is required for enablement, such as that required under 35 U.S.C. §112.

A license may be required to make, use or sell the deposited strain, and compounds derived therefrom, and no such license is hereby granted.

Polypeptides

The polypeptides of the invention include the polypeptide of Table 1 [SEQ ID NO:2] (in particular the mature polypeptide) as well as polypeptides and fragments, particularly those which have the biological activity of Divlb, and also those which have at least 70% identity to a polypeptide of Table 1 [SEQ ID NOS:2 and 4] or the relevant portion, preferably at least 80% identity to a polypeptide of Table 1 [SEQ ID NOS:2 and 4], and more preferably at least 90% similarity (more preferably at least 90% identity) to a polypeptide of Table 1 [SEQ ID NOS:2 and 4] and still more preferably at least 95% similarity (still more preferably at least 95% identity) to a polypeptide of Table 1 [SEQ ID NOS:2 and 4] and also include portions of such polypeptides with such portion of the polypeptide generally containing at least 30 amino acids and more preferably at least 50 amino acids.

The invention also includes polypeptides of the formula set forth in Table 1 (D) [SEQ ID NO:2] wherein, at the amino terminus, X is hydrogen, and at the carboxyl terminus, Y is hydrogen or a metal, R₁ and R₂ is any amino acid residue, and n is an integer beteen 1 and 1000. Any stretch of amino acid residues denoted by either R group, where R is greater than 1, may be either a heteropolymer or a homopolymer, preferably a heteropolymer.

A fragment is a variant polypeptide having an amino acid sequence that entirely is the same as part but not all of the amino acid sequence of the aforementioned polypeptides. As with Divlb polypeptides fragments may be "free-standing," or comprised within a larger polypeptide of which they form a part or region, most preferably as a single continuous region, a single larger polypeptide.

Preferred fragments include, for example, truncation polypeptides having a portion of an amino acid sequence of Table 1 [SEQ ID NOS:2 and 4], or of variants thereof such as a continuous series of residues that includes the amino terminus, or a continuous series of residues that includes the carboxyl terminus. Degradation forms of the polypeptides of the invention in a host cell, particularly a Staphylococcus aureus, are also preferred. Further preferred are fragments characterized by structural or functional attributes such as fragments that comprise alpha-helix and alpha-heIix forming regions, beta-sheet and beta-sheet-forming regions, turn and turn-forming regions, coil and coil-forming regions, hydrophilic regions, hydrophobic regions, alpha amphipathic regions, beta amphipathic regions, flexible regions, surface-forming regions, substrate binding region, and high antigenic index regions.

Also preferred are biologically active fragments which are those fragments that mediate activities of Divlb, including those with a similar activity or an improved activity, or with a decreased undesirable activity. Also included are those fragments that are antigenic or immunogenic in an animal, especially in a human. Particularly preferred are fragments comprising receptors or domains of enzymes that confer a function essential for viability of Staphylococcus aureus or the ability to initiate, or maintain cause disease in an individual, particularly a human.

Variants that are fragments of the polypeptides of the invention may be employed for producing the corresponding full-length polypeptide by peptide synthesis; therefore, these variants maybe employed as intermediates for producing the full-length polypeptides of the invention.

Polynucleotides

Another aspect of the invention relates to isolated polynucleotides, including the full length gene, that encode the Divlb polypeptide having a deduced amino acid sequence of Table 1 [SEQ ID NOS:2 and 4] and polynucleotides closely related thereto and variants thereof.

Using the information provided herein, such as a polynucleotide sequence set out in Table 1 [SEQ ID NOS:1 and 3], a polynucleotide of the invention encoding Divlb polypeptide may be obtained using standard cloning and screening methods, such as those for cloning and sequencing chromosomal DNA fragments from bacteria using Staphylococcus aureus WCUH 29 cells as starting material, followed by obtaining a full length clone. For example, to obtain a polynucleotide sequence of the invention, such as a sequence given in Table 1 [SEQ ID NOS: 1 and 3], typically a library of clones of chromosomal DNA of Staphylococcus aureus WCUH 29 in E. coli or some other suitable host is probed with a radiolabeled oligonucleotide, preferably a 17-mer or longer, derived from a partial sequence. Clones carrying DNA identical to that of the probe can then be distinguished using stringent conditions. By sequencing the individual clones thus identified with sequencing primers designed from the original sequence it is then possible to extend the sequence in both directions to determine the full gene sequence. Conveniently, such sequencing is performed using denatured double stranded DNA prepared from a plasmid clone. Suitable techniques are described by Maniatis, T., Fritsch, E. F. and Sambrook et al., MOLECULAR CLONING, A LABORATORY MANUAL, 2nd Ed.; Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989). (see in particular Screening By Hybridization 1.90 and Sequencing Denatured Double-Stranded DNA Templates 13.70). Illustrative of the invention, the polynucleotide set out in Table 1 [SEQ ID NO:1] was discovered in a DNA library derived from Staphylococcus aureus WCUH 29.

The DNA sequence set out in Table 1 [SEQ ID NO:1] contains an open reading frame encoding a protein having about the number of amino acid residues set forth in Table 1 [SEQ ID NO:2] with a deduced molecular weight that can be calculated using amino acid residue molecular weight values well known in the art. The polynucleotide of SEQ ID NO: 1, between nucleotide number 1 through number 1317 encodes the polypeptide of SEQ ID NO:2. The stop codon begins at nucleotide number 1318 of SEQ ID NO:1.

Divlb of the invention is structurally related to other proteins of the div (cell division) family, as shown by the results of sequencing the DNA encoding Divlb of the deposited strain. The protein exhibits greatest homology to FtsQ in E. coli and Divlb in B. subtilis protein among known proteins. Divlb of Table 1 [SEQ ID NO:2] has about 27.9% over its entire length and about 52.5% similarity over its entire length with the amino acid sequence of Divlb in B. subtilis polypeptide.

The invention provides a polynucleotide sequence identical over its entire length to the coding sequence in Table 1 [SEQ ID NO:1]. Also provided by the invention is the coding sequence for the mature polypeptide or a fragment thereof, by itself as well as the coding sequence for the mature polypeptide or a fragment in reading frame with other coding sequence, such as those encoding a leader or secretory sequence, a pre- or pro- or prepro- protein sequence. The polynucleotide may also contain non-coding sequences, including for example, but not limited to non-coding 5' and 3' sequences, such as the transcribed, non-translated sequences, termination signals, ribosome binding sites, sequences that stabilize mRNA, introns, polyadenylation signals, and additional coding sequence which encode additional amino acids. For example, a marker sequence that facilitates purification of the fused polypeptide can be encoded. In certain embodiments of the invention, the marker sequence is a hexa-histidine peptide, as provided in the pQE vector (Qiagen, Inc.) and described in Gentz et al., Proc. Natl. Acad. Sci., USA 86: 821-824 (1989), or an HA tag (Wilson et al., Cell 37: 767 (1984). Polynucleotides of the invention also include, but are not limited to, polynucleotides comprising a structural gene and its naturally associated sequences that control gene expression.

A preferred embodiment of the invention is a polynucleotide of comprising nucleotide 1 to 1317 or 1320 set forth in SEQ ID NO: 1 of Table 1 which encode the Divlb polypeptide.

The invention also includes polynucleotides of the formula set forth in Table 1 (C)[SEQ ID NO: 1] wherein, at the 5' end of the molecule, X is hydrogen, and at the 3' end of the molecule, Y is hydrogen or a metal, R₁ and R₂ is any nucleic acid residue, and n is an integer between 1 and 1000. Any stretch of nucleic acid residues denoted by either R group, adhere R is greater than 1, may be either a heteropolymer or a homopolymer, preferably a heteropolymer.

The term "polynucleotide encoding a polypeptide" as used herein encompasses polynucleotides that include a sequence encoding a polypeptide of the invention, particularly a bacterial polypeptide and more particularly a polypeptide of the Staphylococcus aureus Divlb having the amino acid sequence set out in Table 1 [SEQ ID NO:2]. The term also encompasses polynucleotides that include a single continuous region or discontinuous regions encoding the polypeptide (for example, interrupted by integrated phage or an insertion sequence or editing) together with additional regions, that also may contain coding and/or non-coding sequences.

The invention further relates to variants of the polynucleotides described herein that encode for variants of the polypeptide having the deduced amino acid sequence of Table 1 [SEQ ID NO:2]. Variants that are fragments of the polynucleotides of the invention may be used to synthesize full-length polynucleotides of the invention.

Further particularly preferred embodiments are polynucleotides encoding Divlb variants, that have the amino acid sequence of Divlb polypeptide of Table 1 [SEQ ID NO:2] in which several, a few, 5 to 10, 1 to 5, 1 to 3, 2, 1 or no amino acid residues are substituted, deleted or added, in any combination. Especially preferred among these are silent substitutions, additions and deletions, that do not alter the properties and activities of Divlb.

Further preferred embodiments of the invention are polynucleotides that are at least 70% identical over their entire length to a polynucleotide encoding Divlb polypeptide having an amino acid sequence set out in Table 1 [SEQ ID NOS:2 and 4], and polynucleotides that are complementary to such polynucleotides. Alternatively, most highly preferred are polynucleotides that comprise a region that is at least 80% identical over its entire length to a polynucleotide encoding Divlb polypeptide of the deposited stain and polynucleotides complementary thereto. In this regard, polynucleotides at least 90% identical over their entire length to the same are particularly preferred, and among these particularly preferred polynucleotides, those with at least 95% are especially preferred. Furthermore, those with at least 97% are highly preferred among those with at least 95%, and among these those with at least 98% and at least 99% are particularly highly preferred, with at least 99% being the more preferred.

Preferred embodiments are polynucleotides that encode polypeptides that retain substantially the same biological function or activity as the mature polypeptide encoded by the DNA of Table 1 [SEQ ID NO:1].

The invention further relates to polynucleotides that hybridize to the herein above-described sequences. In this regard, the invention especially relates to polynucleotides that hybridize under stringent conditions to the herein above-described polynucleotides. As herein used, the terms "stringent conditions" and "stringent hybridization conditions" mean hybridization will occur only if there is at least 95% and preferably at least 97% identity between the sequences. An example of stringent hybridization conditions is overnight incubation at 42° C. in a solution comprising: 50% formamide, 5×SSC (150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 micrograms/ml denatured, sheared salmon sperm DNA, followed by washing the hybridization support in 0.1×SSC at about 65° C. Hybridization and wash conditions are well known and exemplified in Sambrook, et al., Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor, N.Y., (1989), particularly Chapter 11 therein.

The invention also provides a polynucleotide consisting essentially of a polynucleotide sequence obtainable by screening an appropriate library containing the complete gene for a polynucleotide sequence set forth in SEQ ID NO:1 or SEQ ID NO:3 under stringent hybridization conditions with a probe having the sequence of said polynucleotide sequence set forth in SEQ ID NO:1 or a fragment thereof; and isolating said DNA sequence. Fragments useful for obtaining such a polynucleotide include, for example, probes and primers described elsewhere herein.

As discussed additionally herein regarding polynucleotide assays of the invention, for instance, polynucleotides of the invention as discussed above, may be used as a hybridization probe for RNA, cDNA and genomic DNA to isolate full-length cDNAs and genomic clones encoding Divlb and to isolate cDNA and genomic clones of other genes that have a high sequence similarity to the Divlb gene. Such probes generally will comprise at least 15 bases. Preferably, such probes will have at least 30 bases and may have at least 50 bases. Particularly preferred probes will have at least 30 bases and will have 50 bases or less.

For example, the coding region of the Divlb gene may be isolated by screening using the DNA sequence provided in SEQ ID NO: 1 to synthesize an oligonucleotide probe. A labeled oligonucleotide having a sequence complementary to that of a gene of the invention is then used to screen a library of cDNA, genomic DNA or mRNA to determine which members of the library the probe hybridizes to.

The polynucleotides and polypeptides of the invention may be employed, for example, as research reagents and materials for discovery of treatments of and diagnostics for disease, particularly human disease, as further discussed herein relating to polynucleotide assays.

Polynucleotides of the invention that are oligonucleotides derived from the sequences of SEQ ID NOS:1 and/or 2 may be used in the processes herein as described, but preferably for PCR, to determine whether or not the polynucleotides identified herein in whole or in part are transcribed in bacteria in infected tissue. It is recognized that such sequences will also have utility in diagnosis of the stage of infection and type of infection the pathogen has attained.

The invention also provides polynucleotides that may encode a polypeptide that is the mature protein plus additional amino or carboxyl-terminal amino acids, or amino acids interior to the mature polypeptide (when the mature form has more than one polypeptide chain, for instance). Such sequences may play a role in processing of a protein from precursor to a mature form, may allow protein transport, may lengthen or shorten protein half-life or may facilitate manipulation of a protein for assay or production, among other things. As generally is the case in vivo, the additional amino acids may be processed away from the mature protein by cellular enzymes.

A precursor protein, having the mature form of the polypeptide fused to one or more prosequences may be an inactive form of the polypeptide. When prosequences are removed such inactive precursors generally are activated. Some or all of the prosequences may be removed before activation. Generally, such precursors are called proproteins.

In sum, a polynucleotide of the invention may encode a mature protein, a mature protein plus a leader sequence (which may be referred to as a preprotein), a precursor of a mature protein having one or more prosequences that are not the leader sequences of a preprotein, or a preproprotein, which is a precursor to a proprotein, having a leader sequence and one or more prosequences, which generally are removed during processing steps that produce active and mature forms of the polypeptide.

Vectors, Host Cells, Expression

The invention also relates to vectors that comprise a polynucleotide or polynucleotides of the invention, host cells that are genetically engineered with vectors of the invention and the production of polypeptides of the invention by recombinant techniques. Cell-free translation systems can also be employed to produce such proteins using RNAs derived from the DNA constructs of the invention.

For recombinant production, host cells can be genetically engineered to incorporate expression systems or portions thereof or polynucleotides of the invention. Introduction of a polynucleotide into the host cell can be effected by methods described in many standard laboratory manuals, such as Davis et al., BASIC METHODS IN MOLECULAR BIOLOGY, (1986) and Sambrook et al., MOLECULAR CLONING: A LABORATORY MANUAL, 2nd Ed, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989), such as, calcium phosphate transfection, DEAE-dextran mediated transfection, transvection, microinjection, cationic lipid-mediated transfection, electroporation, transduction, scrape loading, ballistic introduction and infection.

Representative examples of appropriate hosts include bacterial cells, such as streptococci, staphylococci, enterococci E. coli, streptomyces and Bacillus subtilis cells; fungal cells, such as yeast cells and Aspergillus cells; insect cells such as Drosophila S2 and Spodoptera Sf9 cells; animal cells such as CHO, COS, HeLa, C127, 3T3, BHK, 293 and Bowes melanoma cells; and plant cells.

A great variety of expression systems can be used to produce the polypeptides of the invention. Such vectors include, among others, chromosomal, episomal and virus-derived vectors, e.g., vectors derived from bacterial plasmids, from bacteriophage, from transposons, from yeast episomes, from insertion elements, from yeast chromosomal elements, from viruses such as baculoviruses, papova viruses, such as SV40, vaccinia viruses, adenoviruses, fowl pox viruses, pseudorabies viruses and retroviruses, and vectors derived from combinations thereof, such as those derived from plasmid and bacteriophage genetic elements, such as cosmids and phagemids. The expression system constructs may contain control regions that regulate as well as engender expression. Generally, any system or vector suitable to maintain, propagate or express polynucleotides and/or to express a polypeptide in a host may be used for expression in this regard. The appropriate DNA sequence may be inserted into the expression system by any of a variety of well-known and routine techniques, such as, for example, those set forth in Sambrook et al., MOLECULAR CLONING, A LABORATORY MANUAL, (supra).

For secretion of the translated protein into the lumen of the endoplasmic reticulum, into the periplasmic space or into the extracellular environment, appropriate secretion signals may be incorporated into the expressed polypeptide. These signals may be endogenous to the polypeptide or they may be heterologous signals.

Polypeptides of the invention can be recovered and purified from recombinant cell cultures by well-known methods including ammonium sulfate or ethanol precipitation, acid extraction, anion or cation exchange chromatography, phosphocellulose chromatography, hydrophobic interaction chromatography, affinity chromatography, hydroxylapatite chromataphy, and lectin chromatography. Most preferably, high performance liquid chromatography is employed for purification. Well known techniques for refolding protein may be employed to regenerate active conformation when the polypeptide is denatured during isolation and or purification.

Diagnostic Assays

This invention is also related to the use of the Divlb polynucleotides of the invention for use as diagnostic reagents. Detection of Divlb in a eukaryote, particularly a mammal, and especially a human, will provide a diagnostic method for diagnosis of a disease. Eukaryotes (herein also "individual(s)"), particularly mammals, and especially humans, infected with an organism comprising the Divlb gene may be detected at the nucleic acid level by a variety of techniques.

Nucleic acids for diagnosis may be obtained from an infected individual's cells and tissues, such as bone, blood, muscle, cartilage, and skin. Genomic DNA may be used directly for detection or may be amplified enzymatically by using PCR or other amplification technique prior to analysis. RNA or cDNA may also be used in the same ways. Using amplification, characterization of the species and strain of prokaryote present in an individual, may be made by an analysis of the genotype of the prokaryote gene. Deletions and insertions can be detected by a change in size of the amplified product in comparison to the genotype of a reference sequence. Point mutations can be identified by hybridizing amplified DNA to labeled Divlb polynucleotide sequences. Perfectly matched sequences can be distinguished from mismatched duplexes by RNase digestion or by differences in melting temperatures. DNA sequence differences may also be detected by alterations in the electrophoretic mobility of the DNA fragments in gels, with or without denaturing agents, or by direct DNA sequencing. See, e.g., Myers et al., Science, 230: 1242 (1985). Sequence changes at specific locations also may be revealed by nuclease protection assays, such as RNase and S1 protection or a chemical cleavage method. See, e.g., Cotton et al., Proc. Natl. Acad. Sci., USA, 85: 4397-4401 (1985).

Cells carrying mutations or polymorphisms in the gene of the invention may also be detected at the DNA level by a variety of techniques, to allow for serotyping, for example. For example, RT-PCR can be used to detect mutations. It is particularly preferred to used RT-PCR in conjunction with automated detection systems, such as, for example, GeneScan. RNA or cDNA may also be used for the same purpose, PCR or RT-PCR. As an example, PCR primers complementary to a nucleic acid encoding Divlb can be used to identify and analyze mutations. Examples of representative primers are shown below in Table 2.

                  TABLE 2                                                          ______________________________________                                         Primers for amplification of Div 1b polynucleotides                              SEQ ID NO          PRIMER SEQUENCE                                           ______________________________________                                         5                5'-atggatgataaaacgaagaa-3'                                      6 5'-ttattcttacttgattgttt-3'                                                 ______________________________________                                    

The invention further provides these primers with 1, 2, 3 or 4 nucleotides removed from the 5' and/or the 3' end. These primers may be used for, among other things, amplifying Divlb DNA isolated from a sample derived from an individual. The primers may be used to amplify the gene isolated from an infected individual such that the gene may then be subject to various techniques for elucidation of the DNA sequence. In this way, mutations in the DNA sequence may be detected and used to diagnose infection and to serotype and/or classify the infectious agent.

The invention further provides a process for diagnosing, disease, preferably bacterial infections, more preferably infections by Staphylococcus aureus, and most preferably disease, such as, infections of the upper respiratory tract (e.g., otitis media, bacterial tracheitis, acute epiglottitis, thyroiditis), lower respiratory (e.g., empyema, lung abscess), cardiac (e.g., infective endocarditis), gastrointestinal (e.g., secretory diarrhoea, splenic absces, retroperitoneal abscess), CNS (e.g., cerebral abscess), eye (e.g., blepharitis, conjunctivitis, keratitis, endophthalmitis, preseptal and orbital cellulitis, darcryocystitis), kidney and urinary tract (e.g., epididymitis, intrarenal and perinephric absces, toxic shock syndrome), skin (e.g., impetigo, folliculitis, cutaneous abscesses, cellulitis, wound infection, bacterial myositis) bone and joint (e.g., septic arthritis, osteomyelitis), comprising determining from a sample derived from an individual a increased level of expression of polynucleotide having the sequence of Table 1 [SEQ ID NO: 1]. Increased or decreased expression of Divlb polynucleotide can be measured using any on of the methods well known in the art for the quantitation of polynucleotides, such as, for example, amplification, PCR, RT-PCR, RNase protection, Northern blotting and other hybridization methods.

In addition, a diagnostic assay in accordance with the invention for detecting over-expression of Divlb protein compared to normal control tissue samples may be used to detect the presence of an infection, for example. Assay techniques that can be used to determine levels of a Divlb protein, in a sample derived from a host are well-known to those of skill in the art. Such assay methods include radioimmunoassays, competitive-binding assays, Western Blot analysis and ELISA assays.

Antibodies

The polypeptides of the invention or variants thereof, or cells expressing them can be used as an immunogen to produce antibodies immunospecific for such polypeptides. "Antibodies" as used herein includes monoclonal and polyclonal antibodies, chimeric, single chain, simianized antibodies and humanized antibodies, as well as Fab fragments, including the products of an Fab immunolglobulin expression library.

Antibodies generated against the polypeptides of the invention can be obtained by administering the polypeptides or epitope-bearing fragments, analogues or cells to an animal, preferably a nonhuman, using routine protocols. For preparation of monoclonal antibodies, any technique known in the art that provides antibodies produced by continuous cell line cultures can be used. Examples include various techniques, such as those in Kohler, G. and Milstein, C., Nature 256: 495-497 (1975); Kozbor et al, Immunology Today 4: 72 (1983); Cole et al., pg. 77-96 in MONOCLONAL ANTIBODIES AND CANCER THERAPY, Alan R. Liss, Inc. (1985).

Techniques for the production of single chain antibodies (U.S. Pat. No. 4,946,778) can be adapted to produce single chain antibodies to polypeptides of this invention. Also, transgenic mice, or other organisms such as other mammals, may be used to express humanized antibodies.

Alternatively phage display technology may be utilized to select antibody genes with binding activities towards the polypeptide either from repertoires of PCR amplified v-genes of lymphocytes from humans screened for possessing anti-Divlb or from naive libraries (McCafferty, J. et al., (1990), Nature 348, 552-554; Marks, J. et al., (1992) Biotechnology 10, 779-783). The antigen of these antibodies can also be improved by chain shuffling (Clackson, T. et al., (1991) Nature 352, 624-628).

If two antigen binding domains are present each domain may be directed against a different epitope--termed `bispecific` antibodies.

The above-described antibodies may be employed to isolate or to identify clones expressing the polypeptides to purify the polypeptides by affinity chromatography.

Thus, among others, antibodies against Divib- polypeptide may be employed to treat infections, particularly bacterial infections and especially disease, such as, infections of the upper respiratory tract (e.g., otitis media, bacterial tracbeitis, acute epiglottitis, thyroiditis), lower respiratory (e.g., empyema, lung abscess), cardiac (e.g., infective endocarditis), gastrointestinal (e.g., secretory diarrhoea, splenic absces, retroperitoneal abscess), CNS (e.g., cerebral abscess), eye (e.g., blepharitis, conjunctivitis, keratitis, endophthalmitis, preseptal and orbital cellulitis, darcryocystitis), kidney and urinary tract (e.g., epididymitis, intrarenal and perinephric absces, toxic shock syndrome), skin (e.g., impetigo, folliculitis, cutaneous abscesses, cellulitis, wound infection, bacterial myositis) bone and joint (e.g., septic arthritis, osteomyelitis).

Polypeptide variants include antigenically, epitopically or immunologically equivalent variants that form a particular aspect of this invention. The term "antigenically equivalent derivative" as used herein encompasses a polypeptide or its equivalent which will be specifically recognized by certain antibodies which, when raised to the protein or polypeptide according to the invention, interfere with the immediate physical interaction between pathogen and mammalian host. The term "immunologically equivalent derivative" as used herein encompasses a peptide or its equivalent which when used in a suitable formulation to raise antibodies in a vertebrate, the antibodies act to interfere with the immediate physical interaction between pathogen and mammalian host.

The polypeptide, such as an antigenically or immunologically equivalent derivative or a fusion protein thereof is used as an antigen to immunize a mouse or other animal such as a rat or chicken. The fusion protein may provide stability to the polypeptide. The antigen may be associated, for example by conjugation, with an immunogenic carrier protein for example bovine serum albumin (BSA) or keyhole limpet haemocyanin (KLH). Alternatively a multiple antigenic peptide comprising multiple copies of the protein or polypeptide, or an antigenically or immunologically equivalent polypeptide thereof may be sufficiently antigenic to improve immunogenicity so as to obviate the use of a carrier.

Preferably, the antibody or variant thereof is modified to make it less immunogenic in the individual. For example, if the individual is human the antibody may most preferably be "humanized"; where the complimentarity determining region(s) of the hybridoma-derived antibody has been transplanted into a human monoclonal antibody, for example as described in Jones, P. et al. (1986), Nature 321, 522-525 or Tempest et al., (1991) Biotechnology 9, 266-273.

The use of a polynucleotide of the invention in genetic immunization will preferably employ a suitable delivery method such as direct injection of plasmid DNA into muscles (Wolff et al., Hum Mol Genet 1992, 1:363, Manthorpe et al., Hum. Gene Ther. 1963:4, 419), delivery of DNA complexed with specific protein carriers (Wu et al., J Biol Chem. 1989: 264,16985), coprecipitation of DNA with calcium phosphate (Benvenisty & Reshef, PNAS USA, 1986:83,9551), encapsulation of DNA in various forms of liposomes (Kaneda et al., Science 1989:243,375), particle bombardment (Tang et al., Nature 1992, 356:152, Eisenbraun et al., DNA Cell Biol 1993, 12:791) and in vivo infection using cloned retroviral vectors (Seeger et al., PNAS USA 1984:81,5849).

Antagonists and Agonists--Assays and Molecules

Polypeptides of the invention may also be used to assess the binding of small molecule substrates and ligands in, for example, cells, cell-free preparations, chemical libraries, and natural product mixtures. These substrates and ligands may be natural substrates and ligands or may be structural or functional mimetics. See, e.g., Coligan et al., Current Protocols in Immunology 1(2): Chapter 5 (1991).

The invention also provides a method of screening compounds to identify those which enhance (agonist) or block (antagonist) the action of Divlb polypeptides or polynucleotides, particularly those compounds that are bacteriostatic and/or bactericidal. The method of screening may involve high-throughput techniques. For example, to screen for antagonists or antagonists, a synthetic reaction mix, a cellular compartment, such as a membrane, cell envelope or cell hall, or a preparation of any thereof, comprising Divlb polypeptide and a labeled substrate or ligand of such polypeptide is incubated in the absence or the presence of a candidate molecule that may be a Divlb agonist or antagonist. The ability of the candidate molecule to agonize or antagonize the Divlb polypeptide is reflected in decreased binding of the labeled ligand or decreased production of product from such substrate. Molecules that bind gratuitously, i.e., without inducing the effects of Divlb polypeptide are most likely to be good antagonists. Molecules that bind well and increase the rate of product production from substrate are agonists. Detection of the rate or level of production of product from substrate may be enhanced by using a reporter system. Reporter systems that may be useful in this regard include but are not limited to calorimetric labeled substrate converted into product, a reporter gene that is responsive to changes in Divlb polynucleotide or polypeptide activity, and binding assays known in the art.

Another example of an assay for Divlb antagonists is a competitive assay that combines Divlb and a potential antagonist with Divlb-binding molecules, recombinant Divlb binding molecules, natural substrates or ligands, or substrate or ligand mimetics, under appropriate conditions for a competitive inhibition assay. Divlb can be labeled, such as by radioactivity or a colorimetrc compound, such that the number of Divlb molecules bound to a binding molecule or converted to product can be determined accurately to assess the effectiveness of the potential antagonist.

Potential antagonists include small organic molecules, peptides, polypeptides and antibodies that bind to a polynucleotide or polypeptide of the invention and thereby inhibit or extinguish its activity. Potential antagonists also may be small organic molecules, a peptide, a polypeptide such as a closely related protein or antibody that binds the same sites on a binding molecule, such as a binding molecule, without inducing Divlb-induced activities, thereby preventing the action of Divlb by excluding Divlb from binding.

Potential antagonists include a small molecule that binds to and occupies the binding site of the polypeptide thereby preventing binding to cellular binding molecules, such that normal biological activity is prevented. Examples of small molecules include but are not limited to small organic molecules, peptides or peptide-like molecules. Other potential antagonists include antisense molecules (see Okano, J. Neurochem. 56: 560 (1991); OLIGODEOXYNUCLEOTIDES AS ANTISENSE INHIBITORS OF GENE EXPRESSION, CRC Press, Boca Raton, Fla. (1988), for a description of these molecules). Preferred potential antagonists include compounds related to and variants of Divlb.

Each of the DNA sequences provided herein may be used in the discovery and development of antibacterial compounds. The encoded protein, upon expression, can be used as a target for the screening of antibacterial drugs. Additionally, the DNA sequences encoding the amino terminal regions of the encoded protein or Shine-Delgarno or other translation facilitating sequences of the respective mRNA can be used to construct antisense sequences to control the expression of the coding sequence of interest.

The invention also provides the use of the polypeptide, polynucleotide or inhibitor of the invention to interfere with the initial physical interaction between a pathogen and mammalian host responsible for sequelae of infection. In particular the molecules of the invention may be used: in the prevention of adhesion of bacteria, in particular gram positive bacteria, to mammalian extracellular matrix proteins on in-dwelling devices or to extracellular matrix proteins in wounds; to block Divlb protein-mediated mammalian cell invasion by, for example, initiating phosphorylation of mammalian tyrosine kinases (Rosenshine et al., Infect. Immun. 60:2211 (1992); to block bacterial adhesion between mammalian extracellular matrix proteins and bacterial Divlb proteins that mediate tissue damage and; to block the normal progression of pathogenesis in infections initiated other than by the implantation of in-dwelling devices or by other surgical techniques.

The antagonists and agonists of the invention may be employed, for instance, to inhibit and treat disease, such as, infections of the upper respiratory tract (e.g., otitis media, bacterial tracheitis, acute epiglottitis, thyroiditis), lower respiratory (e.g., empyema, lung abscess), cardiac (e.g., infective endocarditis), gastrointestinal (e.g., secretory diarrhoea, splenic absces, retroperitoneal abscess), CNS (e.g., cerebral abscess), eye (e.g., blepharitis, conjunctivitis, keratitis, endophthalmitis, preseptal and orbital cellulitis, darcryocystitis), kidney and urinary tract (e.g., epididymitis, intrarenal and perinephric absces, toxic shock syndrome), skin (e.g., impetigo, folliculitis, cutaneous abscesses, cellulitis, wound infection, bacterial myositis) bone and joint (e.g., septic arthritis, osteomyelitis).

Vaccines

Another aspect of the invention relates to a method for inducing an immunological response in an individual, particularly a mammal which comprises inoculating the individual with Divlb, or a fragment or variant thereof, adequate to produce antibody and/ or T cell immune response to protect said individual from infection, particularly bacterial infection and most particularly Staphylococcus aureus infection. Also provided are methods whereby such immunological response slows bacterial replication. Yet another aspect of the invention relates to a method of inducing immunological response in an individual which comprises delivering to such individual a nucleic acid vector to direct expression of Divlb, or a fragment or a variant thereof, for expressing Divlb, or a fragment or a variant thereof in vivo in order to induce an immunological response, such as, to produce antibody and/ or T cell immune response, including, for example, cytokine-producing T cells or cytotoxic T cells, to protect said individual from disease, whether that disease is already established within the individual or not. One way of administering the gene is by accelerating it into the desired cells as a coating on particles or otherwise. Such nucleic acid vector may comprise DNA, RNA, a modified nucleic acid, or a DNA/RNA hybrid.

A further aspect of the invention relates to an immunological composition which, when introduced into an individual capable or having induced within it an immunological response, induces an immunological response in such individual to a Divlb or protein coded therefrom, wherein the composition comprises a recombinant Divlb or protein coded therefrom comprising DNA which codes for and expresses an antigen of said Divlb or protein coded therefrom. The immunological response may be used therapeutically or prophylactically and may take the form of antibody immunity or cellular immunity such as that arising from CTL or CD4+T cells.

A Divlb polypeptide or a fragment thereof may be fused with co-protein which may not by itself produce antibodies, but is capable of stabilizing the first protein and producing a fused protein which will have immunogenic and protective properties. Thus fused recombinant protein, preferably further comprises an antigenic co-protein, such as lipoprotein D from Hemophilus influenzae, Glutathione-S-transferase (GST) or beta-galactosidase, relatively large co-proteins which solubilize the protein and facilitate production and purification thereof. Moreover, the co-protein may act as an adjuvant in the sense of providing a generalized stimulation of the immune system. The co-protein may be attached to either the amino or carboxy terminus of the first protein.

Provided by this invention are compositions, particularly vaccine compositions, and methods comprising the polypeptides or polynucleotides of the invention and immunostimulatory DNA sequences, such as those described in Sato, Y. et al. Science 273: 352 (1996).

Also, provided by this invention are methods using the described polynucleotide or particular fragments thereof which have been shown to encode non-variable regions of bacterial cell surface proteins in DNA constructs used in such genetic immunization experiments in animal models of infection with Staphylococcus aureus will be particularly useful for identifying protein epitopes able to provoke a prophylactic or therapeutic immune response. It is believed that this approach will allow for the subsequent preparation of monoclonal antibodies of particular value from the requisite organ of the animal successfully resisting or clearing infection for the development of prophylactic agents or therapeutic treatments of bacterial infection, particularly Staphylococcus aureus infection, in mammals, particularly humans.

The polypeptide may be used as an antigen for vaccination of a host to produce specific antibodies which protect against invasion of bacteria, for example by blocking adherence of bacteria to damaged tissue. Examples of tissue damage include wounds in skin or connective tissue caused, e.g., by mechanical, chemical or thermal damage or by implantation of indwelling devices, or wounds in the mucous membranes, such as the mouth, mammary glands, urethra or vagina.

The invention also includes a vaccine formulation which comprises an immunogenic recombinant protein of the invention together with a suitable carrier. Since the protein may be broken down in the stomach, it is preferably administered parenterally, including, for example, administration that is subcutaneous, intramuscular, intravenous, or intradermal. Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the bodily fluid, preferably the blood, of the individual; and aqueous and non-aqueous sterile suspensions which may include suspending agents or thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example, sealed ampules and vials and may be stored in a freeze-dried condition requiring only the addition of the sterile liquid carrier immediately prior to use. The vaccine formulation may also include adjuvant systems for enhancing the immunogenicity of the formulation, such as oil-in water systems and other systems known in the art. The dosage will depend on the specific activity of the vaccine and can be readily determined by routine experimentation.

While the invention has been described with reference to certain Divlb protein, it is to be understood that this covers fragments of the naturally occurring protein and similar proteins with additions, deletions or substitutions which do not substantially affect the immunogenic properties of the recombinant protein.

Compositions, Kits and Administration

The invention also relates to compositions comprising the polynucleotide or the polypeptides discussed above or their agonists or antagonists. The polypeptides of the invention may be employed in combination with a non-sterile or sterile carrier or carriers for use with cells, tissues or organisms, such as a pharmaceutical carrier suitable for administration to a subject. Such compositions comprise, for instance, a media additive or a therapeutically effective amount of a polypeptide of the invention and a pharmaceutically acceptable carrier or excipient. Such carriers may include, but are not limited to, saline, buffered saline, dextrose, water, glycerol, ethanol and combinations thereof. The formulation should suit the mode of administration. The invention further relates to diagnostic and pharmaceutical packs and kits comprising one or more containers filled with one or more of the ingredients of the aforementioned compositions of the invention.

Polypeptides and other compounds of the invention may be employed alone or in conjunction with other compounds, such as therapeutic compounds.

The pharmaceutical compositions may be administered in any effective, convenient manner including, for instance, administration by topical, oral, anal, vaginal, intravenous, intraperitoneal, intramuscular, subcutaneous, intranasal or intradermal routes among others.

In therapy or as a prophylactic, the active agent may be administered to an individual as an injectable composition, for example as a sterile aqueous dispersion, preferably isotonic.

Alternatively the composition may be formulated for topical application for example in the form of ointments, creams, lotions, eye ointments, eye drops, ear drops, mouthwash, impregnated dressings and sutures and aerosols, and may contain appropriate conventional additives, including, for example, preservatives, solvents to assist drug penetration, and emollients in ointments and creams. Such topical formulations may also contain compatible conventional carriers, for example cream or ointment bases, and ethanol or oleyl alcohol for lotions. Such carriers may constitute from about 1% to about 98% by weight of the formulation; more usually they will constitute up to about 80% by weight of the formulation.

For administration to mammals, and particularly humans, it is expected that the daily dosage level of the active agent will be from 0.01 mg/kg to 10 mg/kg, typically around 1 mg/kg. The physician in any event will determine the actual dosage which will be most suitable for an individual and will vary with the age, weight and response of the particular individual. The above dosages are exemplary of the average case. There can, of course, be individual instances where higher or lower dosage ranges are merited, and such are within the scope of this invention.

In-dwelling devices include surgical implants, prosthetic devices and catheters, i.e., devices that are introduced to the body of an individual and remain in position for an extended time. Such devices include, for example, artficial joints, heart valves, pacemakers, vascular grafts, vascular catheters, cerebrospinal fluid shunts, urinary catheters, continuous ambulatory peritoneal dialysis (CAPD) catheters.

The composition of the invention may be administered by injection to achieve a systemic effect against relevant bacteria shortly before insertion of an in-dwelling device. Treatment may be continued after surgery during the in-body time of the device. In addition, the composition could also be used to broaden perioperative cover for any surgical technique to prevent bacterial wound infections, especially Staphylococcus aureus wound infections.

Many orthopaedic surgeons consider that humans with prosthetic joints should be considered for antibiotic prophylaxis before dental treatment that could produce a bacteremia. Late deep infection is a serious complication sometimes leading to loss of the prosthetic joint and is accompanied by significant morbidity and mortality. It may therefore be possible to extend the use of the active agent as a replacement for prophylactic antibiotics in this situation.

In addition to the therapy described above, the compositions of this invention may be used generally as a wound treatment agent to prevent adhesion of bacteria to matrix proteins exposed in wound tissue and for prophylactic use in dental treatment as an alternative to, or in conjunction with, antibiotic prophylaxis.

Alternatively, the composition of the invention may be used to bathe an indwelling device immediately before insertion. The active agent will preferably be present at a concentration of 1 μg/ml to 10 mg/ml for bathing of wounds or indwelling devices.

A vaccine composition is conveniently in injectable form. Conventional adjuvants may be employed to enhance the immune response. A suitable unit dose for vaccination is 0.5-5 microgram/kg of antigen, and such dose is preferably administered 1-3 times and with an interval of 1-3 weeks. With the indicated dose range, no adverse toxicological effects will be observed with the compounds of the invention which would preclude their administration to suitable individuals.

Each reference disclosed herein is incorporated by reference herein in its entirety. Any patent application to which this application claims priority is also incorporated by reference herein in its entirety.

EXAMPLES

The examples below are carried out using standard techniques, which are well known and routine to those of skill in the art, except where otherwise described in detail. The examples are illustrative, but do not limit the invention.

Example 1 Strain Selection, Library Production and Sequencing

The polynucleotide having the DNA sequence given in SEQ ID NO: 1 was obtained from a library of clones of chromosomal DNA of Staphylococcus aureus in E. coli. The sequencing data from two or more clones containing overlapping Staphylococcus aureus DNAs was used to construct the contiguous DNA sequence in SEQ ID NO:1. Libraries may be prepared by routine methods, for example:

Methods 1 and 2 below.

Total cellular DNA is isolated from Staphylococcus aureus WCUH 29 according to standard procedures and size-fractionated by either of two methods.

Method 1

Total cellular DNA is mechanically sheared by passage through a needle in order to size-fractionate according to standard procedures. DNA fragments of up to 11 kbp in size are rendered blunt by treatment with exonuclease and DNA polymerase, and EcoRI linkers added Fragments are ligated into the vector Lambda ZapII that has been cut with EcoRI, the library packaged by standard procedures and E. coli infected with the packaged library. The library is amplified by standard procedures.

Method 2

Total cellular DNA is partially hydrolyzed with a one or a combination of restriction enzymes appropriate to generate a series of fragments for cloning into library vectors (e.g., RsaI, PalI, AluI, Bshl235I), and such fragments are size-fractionated according to standard procedures. EcoRI linkers are ligated to the DNA and the fragments then ligated into the vector Lambda ZapII that have been cut with EcoRI, the library packaged by standard procedures, and E. coli infected with the packaged library. The library is amplified by standard procedures.

Example 2 Divib Characterization

E. coli FtsQ, H.influenzae FtsQ, B. subtilis DivIB and S. aureus DivIB have similar hydrophobicity profiles. All four proteins contain a highly hydrophobic region of approximately 20 amino acids in length which is indicative of the membrane spanning region. These regions are located towards the N-terminus of the mature peptide. Based on the work by Dai et al., 1996 (J. Bacteriology 178, 1328-1334) on the E. coli homolog, the cytoplasmic and membrane spanning regions of Staph DivlB are dispensible. Therefore, removal of the cytoplasmic and membrane spanning regions of the Staph DivlB protein allows for the evaluation of this protein in the assays below.

Interactions of FtsQ with other cell divsion proteins (e.g., Fts A, Z, N, W, Y) are used as the basis of an assay for identifying agonists or antagonists of DivlB. The measurement of the interaction of DivlB protein with additional proteins or peptides, either within a lipid-based membrane system or in solution, provides for a potential assay format. Heterogeneous assays encompassing the use of an immunoassay or surface-coating format in conjunction with either radiolabelled or optically labelled proteins and components can be used. The interaction of unlabelled DivlB with other polypeptides can also be observed directly using surface plasmon resonance technology in optical biosensor devices. This method is particularly useful for measuring interactions with larger (>5 kDa) polypeptides and can be readily adapted to screen for inhibitors of the protein-protein interaction. Solution-based homogeneous assays using fluorescently-labelled components can be configured to report on changes in fluorescence intensity, fluorescence anisotropy, fluorescence energy transfer or correlation fluctuations in intensity as a result of the binding interaction. Binding proteins useful in these types of assay can be identified by `ligand fishing` using, for example, optical biosensor methods (Bartley et al. 1994, Nature 368: 558) and bacterial extracts followed by affinity capture or chromatography on immobilized DivlB. Following elution of binding proteins from immobilized DivlB using salt, pH changes or chaotropic agents, the eluted protein products can be separated using high-resolution methods such as reverse-phase high performance liquid chromatography and the individual polypeptides characterized by N-terminal amino acid sequencing and/or mass mapping (mass spectrometry combined with molecular ion weight matching against a protein database). Yeast two-hybrid and phage display technologies are also be used to identify ligands which bind to DivlB. Interaction of ligands, identified by the methods described above or otherwise, with DivlB will form the basis of an assay to screen for inhibitors and/or agonists of DivlB.

Pure DivlB protein is used to raise antibodies in mice or rabbits or other suitable animal host. Using standard techniques with materials such as gold-antibody conjugates, fluoresently labelled antibodies or GFP the DivlB protein is localized and the effect of compounds is tested.

    __________________________________________________________________________     #             SEQUENCE LISTING                                                    - -  - - <160> NUMBER OF SEQ ID NOS: 6                                         - - <210> SEQ ID NO 1                                                         <211> LENGTH: 1320                                                             <212> TYPE: DNA                                                                <213> ORGANISM: Staphylococcus aureus                                           - - <400> SEQUENCE: 1                                                          - - atggatgata aaacgaagaa cgatcaacaa gaatcaaatg aagataaaga tg -             #aattagaa     60                                                                  - - ttatttacga ggaatacatc taagaaaaga cggcaaagaa aaaggtcaaa gg -             #ctacacat    120                                                                  - - ttttctaatc aaaataaaga tgatacatct caacaagctg attttgatga ag -             #aaatttac    180                                                                  - - ttgataaata aagacttcaa aaaagaagaa agcaatgatg aaaataatgg tt -             #ctgcttct    240                                                                  - - agtcatgcga atgataataa tatcgatgat tctacagact ctaatattga aa -             #atgaggat    300                                                                  - - tatagatata atcaagaaat tgacgaccaa aatgaatcga atggaattgc ag -             #tcgccaac    360                                                                  - - gaacaacctc aatcagctcc taaagaacaa aatagcgact cgaatgatga gg -             #aaacagta    420                                                                  - - acgaaaaaag agcgaaaaag taaagtaaca caattaaagc cattaacact tg -             #aagaaaag    480                                                                  - - cggaagttaa gacgtaagcg acaaaaacga atccaataca gtgttattac aa -             #tattagta    540                                                                  - - ttgttgattg ctgttatatt aatttacatg ttttcaccac ttagtaaaat tg -             #cgcatgta    600                                                                  - - aatataaatg gaaataatca cgttagtact tcaaagataa acaaagtttt ag -             #gtgttaaa    660                                                                  - - aatgattcga ggatgtatac gtttagtaaa aaaaatgcta ttaatgatct cg -             #aagaggat    720                                                                  - - ccattaatca caagtgttga gatacacaag caattcccaa acacattaaa cg -             #tagatatc    780                                                                  - - acagaaaatg aaattattgc tttagtgaaa tataaaggta aatatttacc tt -             #tattagaa    840                                                                  - - aatggtaaat tgcttaaagg ttcaaatgat gtcaaaatta atgatgcacc tg -             #tcatggat    900                                                                  - - ggtttcaaag gtacaaaaga agatgatatg attaaggcgt tatctgaaat ga -             #cacctgaa    960                                                                  - - gttagacgat atattgccga agtgacatac cccccaagta aaaacaaaca ta -             #gcagaatt   1020                                                                  - - gaattgttta cgacagatgg acttcaagta atcggtgata tttcgacgat at -             #ctaagaaa   1080                                                                  - - atgaaatatt atccgcagat gtcacaatca ttatcaaggg atagttcggg ta -             #aactaaaa   1140                                                                  - - acaagaggct atattgattt atcagtcggt gcttcattta tcccataccg tg -             #gaaacacg   1200                                                                  - - tctagtcaat cagaaagcga taaaaatgtg actaaatcat ctcaagagga aa -             #atcaagca   1260                                                                  - - aaagaagaat tacaaagcgt tttaaacaaa attaacaaac aatcaagtaa ga -             #ataattaa   1320                                                                  - -  - - <210> SEQ ID NO 2                                                    <211> LENGTH: 439                                                              <212> TYPE: PRT                                                                <213> ORGANISM: Staphylococcus aureus                                           - - <400> SEQUENCE: 2                                                          - - Met Asp Asp Lys Thr Lys Asn Asp Gln Gln Gl - #u Ser Asn Glu Asp         Lys                                                                               1               5  - #                10  - #                15               - - Asp Glu Leu Glu Leu Phe Thr Arg Asn Thr Se - #r Lys Lys Arg Arg Gln                   20      - #            25      - #            30                    - - Arg Lys Arg Ser Lys Ala Thr His Phe Ser As - #n Gln Asn Lys Asp Asp               35          - #        40          - #        45                        - - Thr Ser Gln Gln Ala Asp Phe Asp Glu Glu Il - #e Tyr Leu Ile Asn Lys           50              - #    55              - #    60                            - - Asp Phe Lys Lys Glu Glu Ser Asn Asp Glu As - #n Asn Gly Ser Ala Ser       65                  - #70                  - #75                  - #80         - - Ser His Ala Asn Asp Asn Asn Ile Asp Asp Se - #r Thr Asp Ser Asn Ile                       85  - #                90  - #                95                - - Glu Asn Glu Asp Tyr Arg Tyr Asn Gln Glu Il - #e Asp Asp Gln Asn Glu                   100      - #           105      - #           110                   - - Ser Asn Gly Ile Ala Val Ala Asn Glu Gln Pr - #o Gln Ser Ala Pro Lys               115          - #       120          - #       125                       - - Glu Gln Asn Ser Asp Ser Asn Asp Glu Glu Th - #r Val Thr Lys Lys Glu           130              - #   135              - #   140                           - - Arg Lys Ser Lys Val Thr Gln Leu Lys Pro Le - #u Thr Leu Glu Glu Lys       145                 1 - #50                 1 - #55                 1 -       #60                                                                               - - Arg Lys Leu Arg Arg Lys Arg Gln Lys Arg Il - #e Gln Tyr Ser Val         Ile                                                                                              165  - #               170  - #               175              - - Thr Ile Leu Val Leu Leu Ile Ala Val Ile Le - #u Ile Tyr Met Phe Ser                   180      - #           185      - #           190                   - - Pro Leu Ser Lys Ile Ala His Val Asn Ile As - #n Gly Asn Asn His Val               195          - #       200          - #       205                       - - Ser Thr Ser Lys Ile Asn Lys Val Leu Gly Va - #l Lys Asn Asp Ser Arg           210              - #   215              - #   220                           - - Met Tyr Thr Phe Ser Lys Lys Asn Ala Ile As - #n Asp Leu Glu Glu Asp       225                 2 - #30                 2 - #35                 2 -       #40                                                                               - - Pro Leu Ile Thr Ser Val Glu Ile His Lys Gl - #n Phe Pro Asn Thr         Leu                                                                                              245  - #               250  - #               255              - - Asn Val Asp Ile Thr Glu Asn Glu Ile Ile Al - #a Leu Val Lys Tyr Lys                   260      - #           265      - #           270                   - - Gly Lys Tyr Leu Pro Leu Leu Glu Asn Gly Ly - #s Leu Leu Lys Gly Ser               275          - #       280          - #       285                       - - Asn Asp Val Lys Ile Asn Asp Ala Pro Val Me - #t Asp Gly Phe Lys Gly           290              - #   295              - #   300                           - - Thr Lys Glu Asp Asp Met Ile Lys Ala Leu Se - #r Glu Met Thr Pro Glu       305                 3 - #10                 3 - #15                 3 -       #20                                                                               - - Val Arg Arg Tyr Ile Ala Glu Val Thr Tyr Pr - #o Pro Ser Lys Asn         Lys                                                                                              325  - #               330  - #               335              - - His Ser Arg Ile Glu Leu Phe Thr Thr Asp Gl - #y Leu Gln Val Ile Gly                   340      - #           345      - #           350                   - - Asp Ile Ser Thr Ile Ser Lys Lys Met Lys Ty - #r Tyr Pro Gln Met Ser               355          - #       360          - #       365                       - - Gln Ser Leu Ser Arg Asp Ser Ser Gly Lys Le - #u Lys Thr Arg Gly Tyr           370              - #   375              - #   380                           - - Ile Asp Leu Ser Val Gly Ala Ser Phe Ile Pr - #o Tyr Arg Gly Asn Thr       385                 3 - #90                 3 - #95                 4 -       #00                                                                               - - Ser Ser Gln Ser Glu Ser Asp Lys Asn Val Th - #r Lys Ser Ser Gln         Glu                                                                                              405  - #               410  - #               415              - - Glu Asn Gln Ala Lys Glu Glu Leu Gln Ser Va - #l Leu Asn Lys Ile Asn                   420      - #           425      - #           430                   - - Lys Gln Ser Ser Lys Asn Asn                                                       435                                                                     - -  - - <210> SEQ ID NO 3                                                    <211> LENGTH: 990                                                              <212> TYPE: DNA                                                                <213> ORGANISM: Staphylococcus aureus                                           - - <400> SEQUENCE: 3                                                          - - atgaatcgga atggaattgc aagtcggcaa ccggaccaac ctcaatcagc tc -              #ctaaagaa     60                                                                  - - caaaatagcg actcgaatga tgaggaaaca gtaacgaaaa aagaacgaaa aa -             #gtaaagta    120                                                                  - - acacaattaa agccattaac acttgaagaa aagcggaagt taagacgtaa gc -             #gacaaaaa    180                                                                  - - cgaatccaat acagtgttat tacaatatta gtattgttga ttgctgttat at -             #taatttac    240                                                                  - - atgttttcac cacttagtaa aattgcgcat gtaaatataa atggaaataa tc -             #acgttagt    300                                                                  - - acttcaaaga taaacaaagt tttaggtgtt aaaaatgatt cgaggatgta ta -             #cgtttagt    360                                                                  - - aaaaaaaatg ctattaatga tctcgaagag gatccattaa tcaaaagtgt tg -             #agatacac    420                                                                  - - aagcaattac caaacacatt aaacgtagat atcacagaaa atgaaattat tg -             #ctttagtg    480                                                                  - - aaatataaag gtaaatattt acctttatta gaaaatggta aattgcttaa ag -             #gttcaaat    540                                                                  - - gatgtcaaaa ttaatgatgc acctgtcatg gatggtttca aaggtacaaa ag -             #aagatgat    600                                                                  - - atgattaagg cgttatctga aatgacacct gaagttagac gatatattgc cg -             #aagtgaca    660                                                                  - - tacgccccaa gtaaaaacaa acatagcaga attgaattgt ttacgacaga tg -             #gacttcaa    720                                                                  - - gtaatcggtg atatttcgac gatatctaag aaaatgaaat attatccgca ga -             #tgtcacaa    780                                                                  - - tcattatcaa gggatagttc gggtaaacta aaaacaagag gctatattga tt -             #tatcagtc    840                                                                  - - ggtgcttcat ttatcccata ccgtggaaac acgtctagtc aatcagaaag cg -             #ataaaaat    900                                                                  - - gtgactaaat catctcaaga ggaaaatcaa gcaaaagaag aattacaaag cg -             #ttttaaac    960                                                                  - - aaaattaaca aacaatcaag taagaataat         - #                  - #               990                                                                      - -  - - <210> SEQ ID NO 4                                                    <211> LENGTH: 330                                                              <212> TYPE: PRT                                                                <213> ORGANISM: Staphylococcus aureus                                           - - <400> SEQUENCE: 4                                                          - - Met Asn Arg Asn Gly Ile Ala Ser Arg Gln Pr - #o Asp Gln Pro Gln Ser        1               5  - #                10  - #                15                - - Ala Pro Lys Glu Gln Asn Ser Asp Ser Asn As - #p Glu Glu Thr Val Thr                   20      - #            25      - #            30                    - - Lys Lys Glu Arg Lys Ser Lys Val Thr Gln Le - #u Lys Pro Leu Thr Leu               35          - #        40          - #        45                        - - Glu Glu Lys Arg Lys Leu Arg Arg Lys Arg Gl - #n Lys Arg Ile Gln Tyr           50              - #    55              - #    60                            - - Ser Val Ile Thr Ile Leu Val Leu Leu Ile Al - #a Val Ile Leu Ile Tyr       65                  - #70                  - #75                  - #80         - - Met Phe Ser Pro Leu Ser Lys Ile Ala His Va - #l Asn Ile Asn Gly Asn                       85  - #                90  - #                95                - - Asn His Val Ser Thr Ser Lys Ile Asn Lys Va - #l Leu Gly Val Lys Asn                   100      - #           105      - #           110                   - - Asp Ser Arg Met Tyr Thr Phe Ser Lys Lys As - #n Ala Ile Asn Asp Leu               115          - #       120          - #       125                       - - Glu Glu Asp Pro Leu Ile Lys Ser Val Glu Il - #e His Lys Gln Leu Pro           130              - #   135              - #   140                           - - Asn Thr Leu Asn Val Asp Ile Thr Glu Asn Gl - #u Ile Ile Ala Leu Val       145                 1 - #50                 1 - #55                 1 -       #60                                                                               - - Lys Tyr Lys Gly Lys Tyr Leu Pro Leu Leu Gl - #u Asn Gly Lys Leu         Leu                                                                                              165  - #               170  - #               175              - - Lys Gly Ser Asn Asp Val Lys Ile Asn Asp Al - #a Pro Val Met Asp Gly                   180      - #           185      - #           190                   - - Phe Lys Gly Thr Lys Glu Asp Asp Met Ile Ly - #s Ala Leu Ser Glu Met               195          - #       200          - #       205                       - - Thr Pro Glu Val Arg Arg Tyr Ile Ala Glu Va - #l Thr Tyr Ala Pro Ser           210              - #   215              - #   220                           - - Lys Asn Lys His Ser Arg Ile Glu Leu Phe Th - #r Thr Asp Gly Leu Gln       225                 2 - #30                 2 - #35                 2 -       #40                                                                               - - Val Ile Gly Asp Ile Ser Thr Ile Ser Lys Ly - #s Met Lys Tyr Tyr         Pro                                                                                              245  - #               250  - #               255              - - Gln Met Ser Gln Ser Leu Ser Arg Asp Ser Se - #r Gly Lys Leu Lys Thr                   260      - #           265      - #           270                   - - Arg Gly Tyr Ile Asp Leu Ser Val Gly Ala Se - #r Phe Ile Pro Tyr Arg               275          - #       280          - #       285                       - - Gly Asn Thr Ser Ser Gln Ser Glu Ser Asp Ly - #s Asn Val Thr Lys Ser           290              - #   295              - #   300                           - - Ser Gln Glu Glu Asn Gln Ala Lys Glu Glu Le - #u Gln Ser Val Leu Asn       305                 3 - #10                 3 - #15                 3 -       #20                                                                               - - Lys Ile Asn Lys Gln Ser Ser Lys Asn Asn                                                   325  - #               330                                      - -  - - <210> SEQ ID NO 5                                                    <211> LENGTH: 20                                                               <212> TYPE: DNA                                                                <213> ORGANISM: Staphylococcus aureus                                           - - <400> SEQUENCE: 5                                                          - - atggatgata aaacgaagaa            - #                  - #                       - # 20                                                                   - -  - - <210> SEQ ID NO 6                                                    <211> LENGTH: 20                                                               <212> TYPE: DNA                                                                <213> ORGANISM: Staphylococcus aureus                                           - - <400> SEQUENCE: 6                                                          - - ttattcttac ttgattgttt            - #                  - #                       - # 20                                                                  __________________________________________________________________________ 

What is claimed is:
 1. An isolated polynucleotide segment comprising: a first polynucleotide sequence, or the full complement of the entire length of such first polynucleotide sequence, wherein the first polynucleotide sequence (a) is a reference sequence that encodes the amino acid sequence set forth in SEQ ID NO:2, or (b) is identical with the reference sequence except that, over the entire length corresponding to the reference sequence, the first polynucleotide sequence has an average of up to five substitutions, deletions or insertions for every 100 nucleotides of the reference sequence.
 2. The isolated polynucleotide segment of claim 1, comprising the first polynucleotide sequence wherein the first polynucleotide sequence is (a) identical with the reference sequence, or (b) identical with the reference sequence except that, over the entire length corresponding to the reference sequence, the first polynucleotide sequence has an average of up to three substitutions, deletions or insertions for every 100 nucleotides of the reference sequence.
 3. The isolated polynucleotide segment of claim 2, wherein the first polynucleotide sequence encodes a Divlb polypeptide.
 4. The isolated polynucleotide segment of claim 1, wherein the isolated polynucleotide comprises the complement sequence, which is the full complement of the first polynucleotide sequence wherein the first polynucleotide sequence which is (a) identical with the reference sequence, or (b) identical with the reference sequence except that, over the entire length corresponding to the reference sequence, the first polynucleotide sequence has an average of up to three substitutions, deletions or insertions for every 100 nucleotides of the reference sequence.
 5. The isolated polynucleotide segment of claim 4, wherein the first polynucleotide sequence encodes a Divlb polypeptide.
 6. A vector comprising the isolated polynucleotide segment of claim
 1. 7. An isolated host cell transfected with the isolated polynucleotide segment of claim 1 to express the first polynucleotide sequence.
 8. A process for producing a Divlb polypeptide of the first polynucleotide sequence comprising the step of culturing the host cell of claim 7 under conditions sufficient for the production of said polypeptide, which is encoded by the first polynucleotide sequence.
 9. An isolated polynucleotide segment, comprising a first polynucleotide sequence, or the full complement of the entire length of the first polynucleotide sequence, wherein the first polynucleotide sequence is selected from the group consisting of(a) a polynucleotide which encodes the same mature polypeptide, expressed by the Divlb gene contained in Staphlococcus aureus WCUH 29 contained in NCIMB Deposit No. 40771; and, (b) a nucleic acid sequence identical to the polynucleotide of (a) except that, over the entire length corresponding to the polynucleotide of (a), up to five nucleotides are substituted, deleted or inserted for every 100 nucleotides of the polynucleotide of (a).
 10. An isolated polynucleotide segment of claim 9, wherein the first polynucleotide is selected from the group consisting of the polynucleotide of (a) and a nucleic acid identical to the polynucleotide of (a) except that, over the entire length corresponding to the polynucleotide of (a) up to three nucleotides are substituted, deleted or inserted for every 100 nucleotides of the polynucleotide of (a).
 11. An isolated polynucleotide segment of claim 9 wherein the first polynucleotide sequence encodes the same mature polypeptide expressed by the Divlb gene contained in Staphylococcus aureus WCUH 29 contained in NCIMB Deposit No. 40771, or the full complement of the entire length of such first polynucleotide sequence.
 12. A polynucleotide which encodes a fusion polypeptide and which includes the isolated polynucleotide segment according to claim
 9. 13. The isolated polynucleotide segment of claim 1, wherein the first polynucleotide sequence hybridizes to the complement of a third reference polynucleotide sequence, wherein the third reference polynucleotide sequence is (a) the polynucleotide sequence set forth in SEQ ID NO: 1, or (b) identical with the polynucleotide sequence set forth in SEQ ID NO: 1 except that, over the entire length corresponding to the polynucleotide sequence set forth in SEQ ID NO: 1, the third reference polynucleotide sequence has an average of up to five substitutions, deletions or insertions for every 100 nucleotides of the polynucleotide sequence set forth in SEQ ID NO: 1; and wherein the hybridization conditions include incubation at 42° C. in a solution comprising: 50% formamide, 5×SSC (150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 micrograms/ml denatured, sheared salmon sperm DNA, followed by washing in 0.1×SSC at about 65° C.
 14. An isolated polynucleotide segment of claim 13, wherein the third reference polynucleotide sequence is (a) identical with the polynucleotide sequence set forth in SEQ ID NO: 1 or (b) identical with the polynucleotide sequence set forth in SEQ ID NO: 1 except that, over the entire length corresponding to the polynucleotide sequence set forth in SEQ ID NO: 1, the third reference polynucleotide sequence has an average of up to three substitutions, deletions or insertions for every 100 nucleotides of the polynucleotide sequence set forth in SEQ ID NO:
 1. 15. The isolated polynucleotide segment of claim 1, wherein the first polynucleotide sequence hybridizes to the complement of the polynucleotide sequence of SEQ ID NO: 1, wherein hybridization conditions include incubation at 42° C. in a solution comprising: 50% formamide, 5×SSC (150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 micrograms/ml denatured, sheared salmon sperm DNA, followed by washing in 0.1×SSC at about 65° C.
 16. A recombinant polynucleotide segment comprising nucleotides 1 to 1317 of the polynucleotide sequence set forth in SEQ ID NO: 1, or the full complement of nucleotides 1 to 1317 of the polynucleotide sequence set forth in SEQ ID NO:
 1. 17. A recombinant polynucleotide segment, wherein the recombinant polynucleotide segment (a) encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:2, or (b) is the full complement of the entire length of a polynucleotide sequence that encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:2.
 18. A vector comprising the polynucleotide segment of claim 17, which segment encodes the polypeptide.
 19. An isolated host cell transfected with the polynucleotide segment of claim 17 to express the polynucleotide sequence.
 20. A process for producing a Divlb polypeptide of the polynucleotide sequence comprising the step of culturing a host cell of claim 19 under conditions sufficient for the production of said polypeptide.
 21. The isolated polynucleotide of claim 1, wherein said isolated polynucleotide encodes a Divlb polypeptide that is involved in bacterial cell division.
 22. The isolated polynucleotide of claim 15, wherein said isolated polynucleotide encodes a Divlb polypeptide that is involved in chorismic acid biosynthetic pathway in bacterial cells.
 23. A composition comprising the isolated polynucleotide of claim 21, which polynucleotide is according to the formula:

    X--(R.sub.1).sub.n --(SEO IN NO:1[PN])--(R.sub.2).sub.n --Y

wherein, at the 5' end of the molecule, X is hydrogen, and at the 3' end of the molecule, Y is hydrogen or a metal, each occurrence of R₁ and R₂ is independently any nucleic acid residue and n is an integer between 1 and
 1000. 